Perkiomenville, PA Finnish Contraflow Masonry Heater: Heat Kit Core, Heated Bench, and Chimney Installation

The owner of this new home in Montgomery County, PA is realizing a life long dream: designing and building a low energy home. The design includes a geothermal system, passive solar heating, high R value insulation, a trombe wall, and a clean burning masonry heater.

The owner placed the heater in the best location possible, roughly centered in the home’s floor plan. He also took advantage of the heater’s thermal mass in the passive solar design. The home and heater are positioned for maximum solar gain during the winter months. The sun’s path tracks over the living room and heater almost the entire day. The masonry heater’s completed Heat Kit core is catching the late afternoon sun in the photo below.


The space above the heater opens to the second floor bedrooms. A photo of the heater’s core. firebrick chimney liner, and heated benches seen from the upstairs catwalk.

The completed brick heater will have a heated bench in front and a heated wood box to the right side of the loading doors. The firebrick liner for the heated woodbox is pictured below. The Heat Kit core is wrapped in a fiberglass blanket to allow for thermal expansion.

Below is a photo of the heater’s chimney liner, built with firebricks. The chimney liner, and entire heater, will be wrapped with a brick facing.

The firebrick lining the bench and chimney will add to the thermal mass of the system and increase the heat transfer form the hot exhaust gases. The opening for the simple slide chimney damper can be seen near the top of the firebrick chimney liner in the photo below.

Fire Works Masonry